<?php

    /**
     * PHPExcel_Reader_Abstract
     * Copyright (c) 2006 - 2015 PHPExcel
     * This library is free software; you can redistribute it and/or
     * modify it under the terms of the GNU Lesser General Public
     * License as published by the Free Software Foundation; either
     * version 2.1 of the License, or (at your option) any later version.
     * This library is distributed in the hope that it will be useful,
     * but WITHOUT ANY WARRANTY; without even the implied warranty of
     * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
     * Lesser General Public License for more details.
     * You should have received a copy of the GNU Lesser General Public
     * License along with this library; if not, write to the Free Software
     * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
     * @category   PHPExcel
     * @package    PHPExcel_Reader
     * @copyright  Copyright (c) 2006 - 2015 PHPExcel (http://www.codeplex.com/PHPExcel)
     * @license    http://www.gnu.org/licenses/old-licenses/lgpl-2.1.txt    LGPL
     * @version    ##VERSION##, ##DATE##
     */
    abstract class PHPExcel_Reader_Abstract implements PHPExcel_Reader_IReader {
        /**
         * Read data only?
         * Identifies whether the Reader should only read data values for cells, and ignore any formatting information;
         *        or whether it should read both data and formatting
         * @var    boolean
         */
        protected $readDataOnly = false;
        /**
         * Read empty cells?
         * Identifies whether the Reader should read data values for cells all cells, or should ignore cells containing
         *         null value or empty string
         * @var    boolean
         */
        protected $readEmptyCells = true;
        /**
         * Read charts that are defined in the workbook?
         * Identifies whether the Reader should read the definitions for any charts that exist in the workbook;
         * @var    boolean
         */
        protected $includeCharts = false;
        /**
         * Restrict which sheets should be loaded?
         * This property holds an array of worksheet names to be loaded. If null, then all worksheets will be loaded.
         * @var array of string
         */
        protected $loadSheetsOnly;
        /**
         * PHPExcel_Reader_IReadFilter instance
         * @var PHPExcel_Reader_IReadFilter
         */
        protected $readFilter;
        protected $fileHandle = null;

        /**
         * Read data only?
         *        If this is true, then the Reader will only read data values for cells, it will not read any formatting information.
         *        If false (the default) it will read data and formatting.
         * @return    boolean
         */
        public function getReadDataOnly() {
            return $this->readDataOnly;
        }

        /**
         * Set read data only
         *        Set to true, to advise the Reader only to read data values for cells, and to ignore any formatting information.
         *        Set to false (the default) to advise the Reader to read both data and formatting for cells.
         * @param    boolean $pValue
         * @return    PHPExcel_Reader_IReader
         */
        public function setReadDataOnly($pValue = false) {
            $this->readDataOnly = $pValue;
            return $this;
        }

        /**
         * Read empty cells?
         *        If this is true (the default), then the Reader will read data values for all cells, irrespective of value.
         *        If false it will not read data for cells containing a null value or an empty string.
         * @return    boolean
         */
        public function getReadEmptyCells() {
            return $this->readEmptyCells;
        }

        /**
         * Set read empty cells
         *        Set to true (the default) to advise the Reader read data values for all cells, irrespective of value.
         *        Set to false to advise the Reader to ignore cells containing a null value or an empty string.
         * @param    boolean $pValue
         * @return    PHPExcel_Reader_IReader
         */
        public function setReadEmptyCells($pValue = true) {
            $this->readEmptyCells = $pValue;
            return $this;
        }

        /**
         * Read charts in workbook?
         *        If this is true, then the Reader will include any charts that exist in the workbook.
         *      Note that a ReadDataOnly value of false overrides, and charts won't be read regardless of the IncludeCharts value.
         *        If false (the default) it will ignore any charts defined in the workbook file.
         * @return    boolean
         */
        public function getIncludeCharts() {
            return $this->includeCharts;
        }

        /**
         * Set read charts in workbook
         *        Set to true, to advise the Reader to include any charts that exist in the workbook.
         *      Note that a ReadDataOnly value of false overrides, and charts won't be read regardless of the IncludeCharts value.
         *        Set to false (the default) to discard charts.
         * @param    boolean $pValue
         * @return    PHPExcel_Reader_IReader
         */
        public function setIncludeCharts($pValue = false) {
            $this->includeCharts = (boolean)$pValue;
            return $this;
        }

        /**
         * Get which sheets to load
         * Returns either an array of worksheet names (the list of worksheets that should be loaded), or a null
         *        indicating that all worksheets in the workbook should be loaded.
         * @return mixed
         */
        public function getLoadSheetsOnly() {
            return $this->loadSheetsOnly;
        }

        /**
         * Set which sheets to load
         * @param mixed $value
         *        This should be either an array of worksheet names to be loaded, or a string containing a single worksheet name.
         *        If NULL, then it tells the Reader to read all worksheets in the workbook
         * @return PHPExcel_Reader_IReader
         */
        public function setLoadSheetsOnly($value = null) {
            if ($value === null) {
                return $this->setLoadAllSheets();
            }
            $this->loadSheetsOnly = is_array($value) ? $value : [$value];
            return $this;
        }

        /**
         * Set all sheets to load
         *        Tells the Reader to load all worksheets from the workbook.
         * @return PHPExcel_Reader_IReader
         */
        public function setLoadAllSheets() {
            $this->loadSheetsOnly = null;
            return $this;
        }

        /**
         * Read filter
         * @return PHPExcel_Reader_IReadFilter
         */
        public function getReadFilter() {
            return $this->readFilter;
        }

        /**
         * Set read filter
         * @param PHPExcel_Reader_IReadFilter $pValue
         * @return PHPExcel_Reader_IReader
         */
        public function setReadFilter(PHPExcel_Reader_IReadFilter $pValue) {
            $this->readFilter = $pValue;
            return $this;
        }

        /**
         * Can the current PHPExcel_Reader_IReader read the file?
         * @param     string $pFilename
         * @return boolean
         * @throws PHPExcel_Reader_Exception
         */
        public function canRead($pFilename) {
            // Check if file exists
            try {
                $this->openFile($pFilename);
            } catch (Exception $e) {
                return false;
            }
            $readable = $this->isValidFormat();
            fclose($this->fileHandle);
            return $readable;
        }

        /**
         * Open file for reading
         * @param string $pFilename
         * @throws    PHPExcel_Reader_Exception
         * @return resource
         */
        protected function openFile($pFilename) {
            // Check if file exists
            if (!file_exists($pFilename) || !is_readable($pFilename)) {
                throw new PHPExcel_Reader_Exception("Could not open " . $pFilename . " for reading! File does not exist.");
            }
            // Open file
            $this->fileHandle = fopen($pFilename, 'r');
            if ($this->fileHandle === false) {
                throw new PHPExcel_Reader_Exception("Could not open file " . $pFilename . " for reading.");
            }
        }

        /**
         * Scan theXML for use of <!ENTITY to prevent XXE/XEE attacks
         * @param     string $filestream
         * @throws PHPExcel_Reader_Exception
         */
        public function securityScanFile($filestream) {
            return $this->securityScan(file_get_contents($filestream));
        }

        /**
         * Scan theXML for use of <!ENTITY to prevent XXE/XEE attacks
         * @param     string $xml
         * @throws PHPExcel_Reader_Exception
         */
        public function securityScan($xml) {
            $pattern = '/\\0?' . implode('\\0?', str_split('<!DOCTYPE')) . '\\0?/';
            if (preg_match($pattern, $xml)) {
                throw new PHPExcel_Reader_Exception('Detected use of ENTITY in XML, spreadsheet file load() aborted to prevent XXE/XEE attacks');
            }
            return $xml;
        }
    }
